Viscosity Control for Extrusion Processes Using Recycled Polymers

The aim of this paper is to develop a new extruder control system for recycled materials which has ability to automatically maintain constant a polymer melt viscosity of mixed recycled polymers during extrusion, regardless of variations in the Melt Flow Index (MFI) of recycled mixed grade high density polyethylene (HDPE) feedstock. A closed-loop controller is developed to automatically regulate screw speed and barrel temperature profile to achieve constant viscosity and enable consistent processing of variable grade recycled HDPE materials. The experimental results of real time viscosity measurement and control using a 38mm single screw extruder with different recycled HDPEs with widely different MFIs are reported in this work

Tooth replacement for partially dentate elders: a randomised controlled trial

Objective: This study aimed to compare two different tooth replacement strategies for partially dentate older patients namely; removable partial dentures (RPDs) and functionally orientated treatment based on the shortened dental arch (SDA) concept. Method: 88 partially dentate older patients (mean age 69.4 years) completed a randomised controlled clinical trial. 43 patients received RPDs and 45 received functionally orientated treatment where resin bonded bridgework was used to provide 10 pairs of occluding contacts. Patients were followed for 1 year after treatment intervention. The impact of treatment on oral health-related quality of life (OHrQOL) and cost effectiveness were used as outcome measures. Each patient completed the short form of the Oral Health Impact Profile (OHIP-14) at baseline, 6 months and 1 year after treatment intervention. All costs involved in providing and maintaining each intervention were recorded including dental laboratory bills, materials and professional time. Result: Both the RPD (p=0.004) and the functionally orientated (p<0.001) treatment groups demonstrated statistically significant improvements in OHrQOL 1 year after treatment intervention. On average 9.4 visits were required to complete and maintain the RPDs over the 1 year period as compared to 5.3 visits for the functionally orientated group. The average laboratory cost for the RPDs was $537.45 per patient versus $367.89 for functionally orientated treatment. The cost of achieving the Minimally Important Difference of 5 scale points in OHIP-14 score with RPDs was $732.17. For the functionally orientated group the cost was $356.88. Therefore, functionally orientated treatment was more than twice as cost effective (1:2.05). Conclusion: For partially dentate older patients, functionally orientated treatment based on the SDA concept resulted in sustained, significant improvements in OHrQOL. Provision of functionally orientated treatment was also more than twice as cost effective compared to conventional treatment using RPDs.

Cost Effectiveness of Tooth Replacement Strategies for Partially Dentate Elders

Objectives: This study aimed to compare the cost effectiveness of conventional treatment using partial dentures with functionally-orientated treatment based on the shortened dental arch concept to replace missing teeth for partially dentate elders.
Methods: 44 partially dentate patients aged 65 years and older were recruited following routine dental assessment at a university dental hospital. Patients consented to and were randomly assigned to the two treatment arms. The conventional treatment group received a removable partial denture to replace all missing natural teeth. The functionally-orientated group were restored to a shortened dental arch of 10 occluding contacts using resin bonded bridgework. The costs associated with each treatment were recorded including laboratory charges, treatment time and opportunity costs. The impact on quality of life (OHRQoL) was measured using the 14-item Oral Health Impact Profile.
Results: Both groups reported improvements in OHRQoL after completion of treatment. For the conventional group, the mean OHIP-14 score decreased from 12.4 pre-operatively to 3.3 post-operatively (p<0.001). In the functionally-orientated group the OHIP-14 score decreased from 11.4 to 1.8 following treatment (p<0.001). On average the conventional treatment group required 8.3 clinic visits as compared to 4.4 visits for the functionally-orientated group. The mean total treatment time was 183 minutes 19 seconds for the conventional group versus 124 minutes 8 seconds for the functionally-orientated group. The conventional treatment group had an average of 6.33 teeth replaced at a laboratory cost of 337.31 Euros. The functionally-orientated group had an average of 2.64 teeth replaced at a laboratory cost of 244.05 Euros.
Conclusions: Restoration to a shortened dental arch using functionally-orientated treatment resulted in a similar improvement in OHRQoL with fewer clinic visits, less operative time and at a lower laboratory cost compared with conventional treatment.

A Coordination and Ligand Replacement Based Three-Input Colorimetric Logic Gate Sensing Platform for Melamine, Mercury Ions, and Cysteine

Discrimination of different species in various target scopes within a single sensing platform can provide many advantages such as simplicity, rapidness, and cost effectiveness. Here we design a three-input colorimetric logic gate based on the aggregation and anti-aggregation of gold nanoparticles (Au NPs) for the sensing of melamine, cysteine, and Hg2+. The concept takes advantages of the highly specific coordination and ligand replacement reactions between melamine, cysteine, Hg2+, and Au NPs. Different outputs are obtained with the combinational inputs in the logic gates, which can serve as a reference to discriminate different analytes within a single sensing platform. Furthermore, besides the intrinsic sensitivity and selectivity of Au NPs to melamine-like compounds, the “INH” gates of melamine/cysteine and melamine/Hg2+ in this logic system can be employed for sensitive and selective detections of cysteine and Hg2+, respectively.

Fluid balance, intradialytic hypotension, and outcomes in critically ill patients undergoing renal replacement therapy: a cohort study

Introduction: In this cohort study, we explored the relationship between fluid balance, intradialytic hypotension and outcomes in critically ill patients with acute kidney injury (AKI) who received renal replacement therapy (RRT).

Methods: We analysed prospectively collected registry data on patients older than 16 years who received RRT for at least two days in an intensive care unit at two university-affiliated hospitals. We used multivariable logistic regression to determine the relationship between mean daily fluid balance and intradialytic hypotension, both over seven days following RRT initiation, and the outcomes of hospital mortality and RRT dependence in survivors.

Results: In total, 492 patients were included (299 male (60.8%), mean (standard deviation (SD)) age 62.9 (16.3) years); 251 (51.0%) died in hospital. Independent risk factors for mortality were mean daily fluid balance (odds ratio (OR) 1.36 per 1000 mL positive (95% confidence interval (CI) 1.18 to 1.57), intradialytic hypotension (OR 1.14 per 10% increase in days with intradialytic hypotension (95% CI 1.06 to 1.23)), age (OR 1.15 per five-year increase (95% CI 1.07 to 1.25)), maximum sequential organ failure assessment score on days 1 to 7 (OR 1.21 (95% CI 1.13 to 1.29)), and Charlson comorbidity index (OR 1.28 (95% CI 1.14 to 1.44)); higher baseline creatinine (OR 0.98 per 10 mu mol/L (95% CI 0.97 to 0.996)) was associated with lower risk of death. Of 241 hospital survivors, 61 (25.3%) were RRT dependent at discharge. The only independent risk factor for RRT dependence was pre-existing heart failure (OR 3.13 (95% CI 1.46 to 6.74)). Neither mean daily fluid balance nor intradialytic hypotension was associated with RRT dependence in survivors. Associations between these exposures and mortality were similar in sensitivity analyses accounting for immortal time bias and dichotomising mean daily fluid balance as positive or negative. In the subgroup of patients with data on pre-RRT fluid balance, fluid overload at RRT initiation did not modify the association of mean daily fluid balance with mortality.

Conclusions: In this cohort of patients with AKI requiring RRT, a more positive mean daily fluid balance and intradialytic hypotension were associated with hospital mortality but not with RRT dependence at hospital discharge in survivors.

Recycling of demolition waste in Merseyside

There have been considerable developments in Merseyside over the last fifteen years with regards to the commercialisation of recycled demolition aggregate. Liverpool is an urban region that at the time was undergoing regeneration. This required the demolition of old infrastructure. Subsequent reconstruction required new construction materials. A project started in 2001 to investigate the economics, practicalities and technicalities of using recycled demolition aggregates in concrete precast products. It was estimated that if all six demolition contractors around Liverpool worked round the clock (i.e. assuming there was enough feed material) they would still have found it difficult to maintain the required supplies for a single precast factory. Investment in equipment was therefore required to guarantee supply and improve the quality of the recycled demolition aggregate. The market forces and the incentives/drivers for construction companies to adopt sustainable practises have encouraged investment of several million pounds to be made in new recycling plants and has resulted in ‘urban quarries’. This paper describes the developments in recycling of construction and demolition waste over the last decade in Merseyside and shows that recycling is not only sustainable but also profitable.

Tooth replacement for partially dentate elders: a willingness-to-pay analysis

Objectives: The primary aim of this study was to investigate partially dentate elders’ willingness-to-pay (WTP) for two different tooth replacement strategies: using Removable Partial Dentures (RPDs) and, functionally orientated treatment (SDA). The secondary aim was to measure the same patient group’s WTP for dental implants. Methods: Patients who had completed a previous RCT comparing two tooth replacement strategies (RPDs and SDA) were recruited. 59 patients were asked to indicate their WTP for treatment to replace missing teeth in a number of hypothetical scenarios using the payment card method of contingency evaluation coupled to different costs. Data were collected on patients’ social class, longest held occupation, income levels and social circumstances. Results: The median age for the patient sample was 72.0 years (IQR: 71-75 years). Patients who had previously been provided with RPDs indicated that their WTP for this treatment strategy was significantly higher than those patients who had received SDA treatment (Mann-Whitney U Test: p<0.001). This group were also WTP a higher price for SDA treatment than those patients who had previously been treated according to this modality (Mann-Whitney U Test: p=0.005). The results indicated that patients’ age was not correlated with WTP but both social class and current income levels were significantly correlated (Spearman’s rank correlation: p<0.05). Patients in both treatment groups exhibited llittle WTP for dental implant treatment with a median price recorded which was lower than either RPD or SDA treatment. Conclusions: Amongst this patient cohort previous treatment experience had a strong influence on WTP as did social class and current income levels. The patients’ WTP indicated that they did not value dental implants over simpler forms of tooth replacement such as RPDs or a SDA approach.

The influence of area level social deprivation on preoperative disease severity and postoperative outcomes following unicompartmental knee joint replacement

BACKGROUND: This study investigated the effect of socioeconomic deprivation on preoperative disease and outcome following unicompartmental knee replacement (UKR).

METHODS: 307 Oxford UKRs implanted between 2008 and 2013 under the care of one surgeon using the same surgical technique were analysed. Deprivation was quantified using the Northern Ireland Multiple Deprivation Measure. Preoperative disease severity and postoperative outcome were measured using the Oxford Knee Score (OKS).

RESULTS: There was no difference in preoperative OKS between deprivation groups. Preoperative knee range of motion (ROM) was significantly reduced in more deprived patients with 10° less ROM than least deprived patients. Postoperatively there was no difference in OKS improvement between deprivation groups (p=0.46), with improvements of 19.5 and 21.0 units in the most and least deprived groups respectively. There was no significant association between deprivation and OKS improvement on unadjusted or adjusted analysis. Preoperative OKS, Short Form 12 mental component score and length of stay were significant independent predictors of OKS improvement. A significantly lower proportion of the most deprived group (15%) reported being able to walk an unlimited distance compared to the least deprived group (41%) one year postoperatively.

CONCLUSION: More deprived patients can achieve similar improvements in OKS to less deprived patients following UKR.

LEVEL OF EVIDENCE: 2b - retrospective cohort study of prognosis.

An invasive-native mammalian species replacement process captured by camera trap survey random encounter models

Camera traps are used to estimate densities or abundances using capture-recapture and, more recently, random encounter models (REMs). We deploy REMs to describe an invasive-native species replacement process, and to demonstrate their wider application beyond abundance estimation. The Irish hare Lepus timidus hibernicus is a high priority endemic of conservation concern. It is threatened by an expanding population of non-native, European hares L. europaeus, an invasive species of global importance. Camera traps were deployed in thirteen 1 km squares, wherein the ratio of invader to native densities were corroborated by night-driven line transect distance sampling throughout the study area of 1652 km2. Spatial patterns of invasive and native densities between the invader’s core and peripheral ranges, and native allopatry, were comparable between methods. Native densities in the peripheral range were comparable to those in native allopatry using REM, or marginally depressed using Distance Sampling. Numbers of the invader were substantially higher than the native in the core range, irrespective of method, with a 5:1 invader-to-native ratio indicating species replacement. We also describe a post hoc optimization protocol for REM which will inform subsequent (re-)surveys, allowing survey effort (camera hours) to be reduced by up to 57% without compromising the width of confidence intervals associated with density estimates. This approach will form the basis of a more cost-effective means of surveillance and monitoring for both the endemic and invasive species. The European hare undoubtedly represents a significant threat to the endemic Irish hare.

Tooth replacement for partially dentate elders: a willingness-to-pay analysis

Objectives: The primary aim of this study was to investigate partially dentate elders’ willingness-to-pay (WTP) for two different tooth replacement strategies: using Removable Partial Dentures (RPDs) and, functionally orientated treatment (SDA). The secondary aim was to measure the same patient group’s WTP for dental implants.Methods: Patients who had completed a previous RCT comparing two tooth replacement strategies (RPDs and SDA) were recruited. 59 patients were asked to indicate their WTP for treatment to replace missing teeth in a number of hypothetical scenarios using the payment card method of contingency evaluation coupled to different costs. Data were collected on patients’ social class, longest held occupation, income levels and social circumstances.Results: The median age for the patient sample was 72.0 years (IQR: 71-75 years). Patients who had previously been provided with RPDs indicated that their WTP for this treatment strategy was significantly higher than those patients who had received SDA treatment (Mann-Whitney U Test: p<0.001). This group were also WTP a higher price for SDA treatment than those patients who had previously been treated according to this modality (Mann-Whitney U Test: p=0.005). The results indicated that patients’ age was not correlated with WTP but both social class and current income levels were significantly correlated (Spearman’s rank correlation: p<0.05).Patients in both treatment groups exhibited llittle WTP for dental implant treatment with a median price recorded which was lower than either RPD or SDA treatment.Conclusions: Amongst this patient cohort previous treatment experience had a strong influence on WTP as did social class and current income levels. The patients’ WTP indicated that they did not value dental implants over simpler forms of tooth replacement such as RPDs or a SDA approach.

Institutional Hybridity in Public Sector Reform: Replacement, Blending, or Layering of Administrative Paradigms

Despite an abundance of studies on hybridization and hybrid forms of organizing, scholarly work has failed to distinguish consistently between specific types of hybridity. As a consequence, the analytical category has become blurred and lacks conceptual clarity. Our paper discusses hybridity as the simultaneous appearance of institutional logics in organizational contexts, and differentiates the parallel co-existence of logics from transitional combinations (eventually leading to the replacement of a logic) and more robust combinations in the form of layering and blending. While blending refers to hybridity as an ‘amalgamate’ with original components that are no longer discernible, the notion of layering conceptualizes hybridity in a way that the various elements, or clusters thereof, are added on top of, or alongside, each other, similar to sediment layers in geology. We illustrate and substantiate such conceptual differentiation with an empirical study of the dynamics of public sector reform. In more detail, we examine the parliamentary discourse around two major reforms of the Austrian Federal Budget Law in 1986 and in 2007/2009 in order to trace administrative (reform) paradigms. Each of the three identified paradigms manifests a specific field-level logic with implications for the state and its administration: bureaucracy in Weberian-style Public Administration, market-capitalism in New Public Management, and democracy in New Public Governance. We find no indication of a parallel co-existence or transitional combination of logics, but hybridity in the form of robust combinations. We explore how new ideas fundamentally build on – and are made resonant with – the central bureaucratic logic in a way that suggests layering rather than blending. The conceptual findings presented in our article have implications for the literature on institutional analysis and institutional hybridity.

Climate drives temporal replacement and nested‐resultant richness patterns of Scottish coastal vegetation

Beta diversity quantifies spatial and/or temporal variation in species composition. It is comprised of two distinct components, species replacement and nestedness, which derive from opposing ecological processes. Using Scotland as a case study and a β-diversity partitioning framework, we investigate temporal replacement and nestedness patterns of coastal grassland species over a 34-yr time period. We aim to 1) understand the influence of two potentially pivotal processes (climate and land-use changes) on landscape-scale (5 × 5 km) temporal replacement and nestedness patterns, and 2) investigate whether patterns from one β-diversity component can mask observable patterns in the other.

We summarised key aspects of climate driven macro-ecological variation as measures of variance, long-term trends, between-year similarity and extremes, for three important climatic predictors (minimum temperature, water-balance and growing degree-days). Shifts in landscape-scale heterogeneity, a proxy of land-use change, was summarised as a spatial multiple-site dissimilarity measure. Together, these climatic and spatial predictors were used in a multi-model inference framework to gauge the relative contribution of each on temporal replacement and nestedness patterns.

Temporal β-diversity patterns were reasonably well explained by climate change but weakly explained by changes in landscape-scale heterogeneity. Climate was shown to have a greater influence on temporal nestedness than replacement patterns over our study period, linking nestedness patterns, as a result of imbalanced gains and losses, to climatic warming and extremes respectively. Important climatic predictors (i.e. growing degree-days) of temporal β-diversity were also identified, and contrasting patterns between the two β-diversity components revealed.

Results suggest climate influences plant species recruitment and establishment processes of Scotland's coastal grasslands, and while species extinctions take time, they are likely to be facilitated by climatic perturbations. Our findings also highlight the importance of distinguishing between different components of β-diversity, disentangling contrasting patterns than can mask one another.